Colorectal cancer prognosis among patients with inflammatory bowel disease

Background & Aims: Inflammatory bowel disease (IBD) is associated with an increased risk for colorectal cancer (CRC). However, the genetic, endoscopic, and histologic features of IBD-associated CRC differ from cancers that arise sporadically. The objectives of this study were to describe the clinicopathologic features of IBD-associated CRC and to compare survival rates between patients with IBD-associated CRC and patients with sporadic CRC. Methods: There were 290 patients with IBD-associated CRC (241 with chronic ulcerative colitis [CUC] and 49 with Crohn's disease) and an equal number of age- and sex-matched sporadic CRC patients who were evaluated at the Mayo Clinic between :1976 and 1996. Medical records were reviewed retrospectively for demographic features, endoscopic and histologic characteristics, and vital status at the time of the last follow-up evaluation. The actuarial survival of each group was calculated by the Kaplan-Meier method. The influence of clinical features on survival was assessed using Cox proportional hazards regression modeling. Results: The median age at diagnosis of IBD-related CRC was 48 years. Fifty-five percent of IBD-related tumors were distal to the splenic flexure compared with 78% of sporadic tumors. During a median follow-up period of 5 years, :163 IBD-associated CRC patients died (56%), compared with 164 sporadic CRC patients (57%). The 5-year survival rates were 54% in the IBD-CRC subgroup vs 53% in the sporadic CRC subgroup (P =.94, log-rank). Conclusions: CUC-related CRC is diagnosed at a relatively young age, and IBD-related tumors tend to be distributed more evenly across the colorectum than sporadic tumors. The survival rates for IBD-associated and sporadic CRC were similar.